/Engine/Source/Runtime/Core/Public/ProfilingDebugging/Histogram.h
Returns a string in a Json format: [{"BinName":{"Count":Count,"Sum":Sum}},...]. Bucket name is constructed by calling ConvertBinToLabel on the MinValue and UpperBound for each bin. Convert function is used to allow the bin range, which is stored as a double, to be printed prettily.
[FString](API\Runtime\Core\Containers\FString) DumpToJsonString2 ( [TFunctionRef](API\Runtime\Core\GenericPlatform\TFunctionRef)< [FString](API\Runtime\Core\Containers\FString)(double, double)> ConvertBinToLabel ) const